1. Field of the Invention
The present invention relates to a power-branched continuously variable transmission.
2. Description of the Related Art
Continuously variable transmissions, i.e., transmissions having a continuously variable transmission ratio, are being used more often in modern motor vehicles. To increase the transmission range, i.e., the spread of the transmission, and/or to relieve the variable speed drive unit, which is constructed in general as a frictional transmission, and particularly a belt-driven conical-pulley transmission, such continuously variable transmissions have been designed with power branching, as is described in German published patent applications DE 102 47 174 A1 or DE 103 58 114 A1, for example. Even when continuously variable transmissions are constructed with power branching, a start-up clutch, which is usually in the form of a hydrodynamic converter, is usually located at the transmission input between the shaft driven by a drive engine and the input shaft of the transmission
The present invention has as an object the provision of a power-branched continuously variable transmission that operates with a variable speed drive unit having lower torque transmission capability, despite high start-up torque.